1. Field of the Invention
This invention pertains generally to a mass rolling along a track, and more specifically to an apparatus for creating the illusion of a track-guided body rolling unassisted uphill against the pull of gravity and demonstrating the geometrical relationships of the body and the track.
2. Description of the Background Art
Various devices for demonstrating the laws of gravity have been heretofore developed. For example, U.S. Pat. No. 2,603,885 issued to Bates on Jul. 22, 1952, discloses a gravity illustrating toy in which a conical body rolls along a track to create the illusion of rolling uphill. U.S. Pat. No. 2,678,515 issued to Desiderio on May 18, 1954 discloses a rolling wheel toy. U.S. Pat. No. 4,028,818 issued to Warner et al. on Jun. 14, 1977 discloses a tracked incline teaching apparatus. U.S. Pat. No. 4,669,727 issued to David on Jun. 2, 1987, discloses a double-bar riding wheel and method of use. U.S. Pat. No. 2,227,705 issued to Colucci on Jan. 7, 1941 discloses an amusement toy. U.S. Pat. No. 2,167,992 issued to Olsen on Aug. 1, 1939 discloses balancing sticks. U.S. Pat. No. 3,394,489 issued to Martin on Jul. 30, 1968 discloses an article roll game and track therefor. U.S. Pat. No. D-253,179 discloses an ornamental design for a holder for small stationary items.
None of the foregoing devices, however, convincingly create the illusion of a body or mass rolling unassisted uphill against the pull of gravity, while at the same time illustrating the geometric relationships between the rolling body and the track which create the illusion. Furthermore, many of these devices require careful placement of the rolling body on the track to keep it from rolling off. Others must be assembled prior to use and require considerable manual dexterity in their operation. The present invention overcomes those deficiencies and provides for a clear demonstration of gravitational effects on a rolling body.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant's acknowledged duty of candor in disclosing information which may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant's claimed invention.